Gyalthum-Ambathan stretch likely to be completed in a week

Kathmandu, December 24

If everything goes as planned, the Gyalthum-Ambathan tunnel stretch of Melamchi Water Supply Project is likely to be completed within a week.

According to the project, of the total 27584.5 metres tunnel only 564 metres remain to be excavated. Only 70 metres remain to be excavated along the Gyalthum-Ambathan stretch. Along the Sindhu-Gyalthum stretch, 494 metres remain to be excavated.

Deputy Executive Director at Melamchi Water Supply Development Board Bhoj Bikram Thapa said the Gyalthum-Ambathan stretch would be completed within December.

“To complete the work on time, we will continue digging the tunnel even on Christmas and other public holidays,”Thapa told The Himalayan Times, adding, that tunnel excavation along the Gyalthum-Ambathan stretch was running at the rate of seven metres per day.

Though another stretch of the tunnel — Sindhu-Gyalthum — is also close to breakthrough, class-V weak rocks have decelerated the excavation work.

“Due to appearance of weak rocks, the tunnel excavation speed sometimes hits as low as two metres per day,” Thapa said. He, however, claimed that the project would complete the section through use of advanced technology by January.

The 27.5 km tunnel comprises three stretches — Sundarijal-Sindhu, Sindhu-Gyalthum and Gyalthum-Ambathan. Three stretches cover 9.5 km, 8 km and 9 km respectively. Of the three adit tunnels, the longest stretch Sundarijal-Sidhu, which covers 9.5 km, was completed on December 28 last year.

The project has imported eight transit mixers from Bangalore of India for concretisation of the Melamchi waterway tunnel. It is said that after the mixers arrive, tunnel concretisation work will move ahead at a pace of 200 metres a day. MWSP contractor CMC Cooperativa Muratori e Cementisti di Ravenna has already promised to complete the work within 100 days of arrival of the equipment.

It is said six to 12 inches thick roller-compacted concrete will be maintained across the invert lining depending upon the hardness of the rock. The remaining wall will be plastered normally.

The Melamchi project’s first deadline expired in 2007 and second deadline in 2016. On April 3 this year, the deadline was extended to October 2017.

Started December in 2000, the Melamchi Water Supply Project is assisted by the Asian Development Bank and aims to reduce drinking water scarcity in the Valley. The project envisages supplying 510,000,000 litres (170,000,000 MLD in first phase and remaining 340,000,000 MLD in second phase) of water per day to Valley from the Melamchi, Yangri, and Larke rivers of Sindhupalchowk district.